Science Objectives of the Ganymede Laser Altimeter (GALA) for the JUICE Mission

Laser altimetry is a powerful tool for addressing the major objectives of planetary physics and geodesy, and have been applied in planetary explorations of the Moon, Mars, Mercury, and the asteroids Eros, and Itokawa. The JUpiter Icy Moons Explorer (JUICE), led by European Space Agency (ESA), has started development to explore the emergence of habitable worlds around gas giants. The Ganymede Laser Altimeter (GALA) will be the first laser altimeter for icy bodies, and will measure the shape and topography of the large icy moons of Jupiter, (globally for Ganymede, and using flyby ground-tracks for Europa and Callisto). Such information is crucial for understanding the formation of surface features and can tremendously improve our understanding of the icy tectonics. In addition, the GALA will infer the presence or absence of a subsurface ocean by measuring the tidal and rotational responses. Furthermore, it also improves the accuracy of gravity field measurements reflecting the interior structure, collaborating with the radio science experiment. In addition to range measurements, the signal strength and the waveform of the laser pulses reflected from the moon's surface contain information about surface reflectance at the laser wavelength and small scale roughness. Therefore we can infer the degrees of chemical and physical alterations, e.g., erosion, space weathering, compaction and deposition of exogenous materials, through GALA measurements without being affected by illumination conditions. JUICE spacecraft carries ten science payloads including GALA. They work closely together in a synergistic way with GALA being one of the key instruments for understanding the evolution of the icy satellites Ganymede, Europa, and Callisto.Comment: 10 pages, 6 figures, accepted for publication in Trans. JSASS Aerospace Tech. Japa

The Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moons Explorer (JUICE): Mission, science, and instrumentation of its receiver modules

The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan’s contribution

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Study on Selective Oxygen Transfer Reactions with Hydrogen Peroxide by Polyoxometalate Catalysts

本研究では、過酸化水素を酸化剤とした選択酸化反応において、従来にはない高い選択率・過酸化水素有効利用率を示す新規なポリオキソメタレート触媒を開発し、オレフィン・スルフィド・アリル型アルコールなど様々な有機基質の選択的酸素添加反応へと応用した。第1章では、過酸化水素や分子状酸素などのクリーンな酸化剤を用いたグリーン酸化触媒を中心に有機合成化学・有機工業化学プロセスにおける選択酸化反応の重要性について述べた後、ポリオキソメタレートを用いた均一系・不均一系選択酸化触媒の設計指針を示し、本研究の目的について述べた。第2章では、チタンの酸化剤活性化能に注目し、単核及び複核の活性点構造をポリオキソメタレート内に構築しその反応性を検討した。Ti-(OH)2-Tiサイトを持ち二量体構造を有する、新規チタン二置換シリコタングステートのみが過酸化水素を用いたオレフィンやスルフィドの酸化反応に活性であり、チタン多核サイトが過酸化水素を活性化する有用な活性点であることを示した。第3章では、チタン二置換シリコタングステートよりも高活性であり、温和な条件下で反応性の低いプロピレンを含むC3-C12の広範なオレフィン類のエポキシ化反応を効率良く促進する新規二原子欠損型シリコタングステートを開発し、従来触媒にはない99%以上という高いエポキシド選択率・過酸化水素有効利用率を実現した。ポリオキソメタレート骨格内に求電子的な酸化活性種が生成することを示し、非共役ジエン類のエポキシ化反応において単核錯体や量論試剤では発現しない特異的選択性を実現した。また、高活性ヒドロペルオキソ種の生成を提案し、効率的酸素添加におけるO-O結合分極化の必要性を示した。第4章では、有機溶媒を全く使用しない、水溶性二核タングステンペルオキソ錯体触媒による水溶媒中でのアリル型アルコールの高効率エポキシ化反応系を開発した。基質に対して等量の過酸化水素のみを酸化剤とし、官能基・位置・ジアステレオ選択的及び立体特異的なアリル型アルコールのエポキシ化反応を実現した。最後に、本研究を総括した。本研究で得られた知見は、有機工業プロセス触媒としての工業的応用が期待される共に、無機化学・触媒化学・錯体化学などの基礎研究分野においても重要であり、立体・形状選択性などの高次な選択性を発現する新規均一系・不均一系触媒の開発・設計に役立つものと期待される。報告番号: 乙16652 ; 学位授与年月日: 2006-11-16 ; 学位の種別: 論文博士 ; 学位の種類: 博士(工学) ; 学位記番号: 第16652号 ; 研究科・専攻: 工学系研究科応用化学専

Base Catalysis by Mono- and Polyoxometalates

In sharp contrast with acid-, photo-, and oxidation-catalysis by polyoxometalates, base catalysis by polyoxometalates has scarcely been investigated. The use of polyoxometalates as base catalysts have very recently received much attention and has been extensively investigated. Numerous mono- and polyoxometalate base catalyst systems effective for the chemical fixation of CO2, cyanosilylation of carbonyl compounds, and C–C bond forming reactions have been developed. Mono- and polyoxometalate base catalysts are classified into four main groups with respect to their structures: (a) monomeric metalates; (b) isopolyoxometalates; (c) heteropolyoxometalates; and (d) transition-metal-substituted polyoxometalates. This review article focuses on the relationship among the molecular structures, the basic properties, and the unique base catalysis of polyoxometalates on the basis of groups (a)–(d). In addition, reaction mechanisms including the specific activation of substrates and/or reagents such as the abstraction of protons, nucleophilic action toward substrates, and bifunctional action in combination with metal catalysts are comprehensively summarized